Thanks for all the info..it's appreciated. Tom
The red 'emergency' light had a very specific purpose on double-track railroads: it was intended as advanced warning to keep opposing traffic from plowing into derailed cars or shifted loads on the train that had 'emergency stopped'. Note that this is different from sending flagging protection to prevent rear-end issues.
Both Milwaukee and UP applied red lights to some of their steam locomotives in the latter '40s for this purpose, as I believe did C&NW -- I don't recall which of these oscillated too.
Some railroads had their standard headlight on top, and a secondary light like a red warning light or Mars light, in the lower light. However, most railroads using a Mars or similar moving light pretty soon came to prefer the regular headlight in the lower light, and the Mars light in the upper.
It appears with the Lackawanna that their freight F-units had the regular headlight on top with a small red warning light in the lower, while passenger diesels (Es and some Fs) had the regular headlight in the lower light and Mars light in the upper.
Some railroads had the red light set so it came on anytime the emergency brake was used. Also, some railroads had both a red emergency light and a Mars-type light in the same upper light housing.
I was almost run over by an old drunk with a bright red nose.....does that count?
Thanks, Ed.
I think it means you're about to be run down by a miniature sleigh and nine tiny reindeer.
It takes an iron man to play with a toy iron horse.
The red signal light seems to have been randomly applied to some of the early freight locomotives, FTs and F3s and even some F7s. These were stationary red lamps, not Mars or Gyralights. They are mentioned in Rule 164 in the Lackawanna Book of Rules April 27, 1952:
164. Most road diesel engines and multiple unit cars are equipped with an emergency red light located just under or above the regular head light or with Mars red light just over the regular head light. They are manually controlled by the enginemen. The purpose; day or night, is to provide immediate warning to an opposing train should an emergency indicate that an opposing track may be obstructed. When an emergency or otherwise unusual stop is made the engineman will immediately light the red light, extinguishing same as soon as it is determined that its indication is unnecessary. The regular head light will be extinguished while red light is displayed. The use of this red light in no way relieves employees of their duty to provide full flag protection. 165. When a passenger car equipped with a supplemental red light is operated as the rear car of a train, the red light, in addition to the markers, will be lighted and display red to the rear at all times. The use of this red light in no way relieves employees of their duty to provide full flag protection.
Yet some of the engines had a regular headlight in the door, these are the passenger F3s with a Mars in the top opening:
And some F7s had the red warning lights, too.
The Lackawanna E8s had Mars lights in the upper housing:
Good Luck, Ed
I was just wondering why some of the Lackawanna F3-F7s had red nose lights on the A units. This seems to be especially true for freight engines.